U.S. Pat. No. 4,191,457, issued Mar. 4, 1980 to Arthur R. Zingher, discloses an apparatus for selectively annotating an optically projected transparency by means of a writing light which is directed at the apparent projected image, through the projection optics, and focussed directly adjacent to the transparency. The present invention is directed toward an annotatable recording film which may be used in this apparatus.
The following U.S. Pat. Nos. comprise the closest known prior art: 4,133,688; 4,127,322; 3,684,552; 3,682,684; 3,852,093; 3,843,384; 4,121,196; 4,000,945; 3,892,965; 3,664,858; 3,592,528.
These prior art references disclose various component technologies in which images are formed by thermographic or photochemical processes. None of these references disclose a film which can be utilized in the apparatus for annotating an optically projected transparency.